• Notes:
    1. AY2017/2018 Semester 2, AY2018/2019 Semester 2, bidding data not available.
    2. The bidding statistics are highly non-normal, likely due to being bounded by zero (they cannot bid negative points or have negative bidders). May consider using zero-inflated or poisson regression if considering these statistics as dependent variables.

1 Phase 1: Setting Up Environment, Packages And Loading Data.

1.3 >>Load myBid.RDS

1.5 >>Load myModInfo.RDS

2 Phase 2: Filter, Transform And Merge Data

2.3 >>Transform And Merge

  • Transform
    • Created a new variable Level that denotes whether the module is Level 1, 2, 3 or 4.
    • Created a new variable BpQ that represents Bids per Quota, which is the number of bidders for each available quota of the module, derived from Bidders and Quota. Used as a measure of the popularity of a module, Higher BpQ signifies greater popularity.
    • Created a new variable LessonTime that denotes whether the lecture begins in the morning (before 12pm), in the afternoon (12pm to 4pm), in the evening (after 4pm).
  • Merge
    • Add the information from myModInfo to myBid.

3 Phase 3: Data Diagnostics

  • Plot univariate histograms and bivariate plots using loops for almost every combination of variables.
  • The graphs from this section are predominantly for diagnostics rather than exploration, what I mean is that the graphs from this section would make little sense if one tried to draw insights from them. This is because they are aggregated across all other variables.
    • For example: The mean of Bidders is calculated across all academic years, all bidding rounds, all modules…
  • What I am looking out for in this section are odd patterns, like zeroes in places where they shouldn’t be, missing data, highly non-normal data, variables with outliers, etc…

3.1 Univariate Descriptive Statistics

##       AcadYear   Semester Round      ModuleCode       Level       StartTime         DayText        LessonTime       Quota           Bidders         LowestBid        LowestSuccessfulBid   HighestBid          BpQ          
##  2013/2014:357   1:950    1A:509   PL1101E:  85   Level 1: 85   Min.   : 800   Monday   :341   Morning  : 518   Min.   :  1.00   Min.   :  0.00   Min.   :   0.000   Min.   :   0.0      Min.   :   0.0   Min.   : 0.00000  
##  2015/2016:322   2:913    1B:303   PL3232 :  56   Level 2: 89   1st Qu.:1100   Tuesday  :365   Afternoon:1130   1st Qu.:  3.00   1st Qu.:  1.00   1st Qu.:   0.625   1st Qu.:   0.5      1st Qu.:   1.0   1st Qu.: 0.02667  
##  2014/2015:294            1C:166   PL3235 :  55   Level 3:925   Median :1300   Wednesday:477   Evening  : 215   Median : 14.50   Median :  3.50   Median :   1.000   Median :   1.0      Median : 400.0   Median : 0.35714  
##  2012/2013:237            2A:283   PL3234 :  54   Level 4:764   Mean   :1301   Thursday :402                    Mean   : 23.49   Mean   : 11.93   Mean   :  75.912   Mean   : 261.6      Mean   : 742.3   Mean   : 1.03981  
##  2016/2017:227            2B:291   PL3236 :  54                 3rd Qu.:1500   Friday   :278                    3rd Qu.: 30.50   3rd Qu.:  9.00   3rd Qu.:  10.000   3rd Qu.: 205.5      3rd Qu.:1215.2   3rd Qu.: 1.20000  
##  2011/2012:166            3A:162   PL3233 :  53                 Max.   :1900                                    Max.   :410.00   Max.   :222.00   Max.   :2430.000   Max.   :3459.0      Max.   :4801.0   Max.   :15.00000  
##  (Other)  :260            3B:149   (Other):1506

3.3 Bivariate Plots

3.3.2 Continuous-Continuous

## StartTime ~ Quota

## StartTime ~ Bidders

## StartTime ~ LowestBid

## StartTime ~ LowestSuccessfulBid

## StartTime ~ HighestBid

## StartTime ~ BpQ

## Quota ~ Bidders

## Quota ~ LowestBid

## Quota ~ LowestSuccessfulBid

## Quota ~ HighestBid

## Quota ~ BpQ

## Bidders ~ LowestBid

## Bidders ~ LowestSuccessfulBid

## Bidders ~ HighestBid

## Bidders ~ BpQ

## LowestBid ~ LowestSuccessfulBid

## LowestBid ~ HighestBid

## LowestBid ~ BpQ

## LowestSuccessfulBid ~ HighestBid

## LowestSuccessfulBid ~ BpQ

## HighestBid ~ BpQ

3.3.4 Continuous-Categorical

## AcadYear ~ StartTime

## AcadYear ~ Quota

## AcadYear ~ Bidders

## AcadYear ~ LowestBid

## AcadYear ~ LowestSuccessfulBid

## AcadYear ~ HighestBid

## AcadYear ~ BpQ

## Semester ~ StartTime

## Semester ~ Quota

## Semester ~ Bidders

## Semester ~ LowestBid

## Semester ~ LowestSuccessfulBid

## Semester ~ HighestBid

## Semester ~ BpQ

## Round ~ StartTime

## Round ~ Quota

## Round ~ Bidders

## Round ~ LowestBid

## Round ~ LowestSuccessfulBid

## Round ~ HighestBid

## Round ~ BpQ

## Level ~ StartTime

## Level ~ Quota

## Level ~ Bidders

## Level ~ LowestBid

## Level ~ LowestSuccessfulBid

## Level ~ HighestBid

## Level ~ BpQ

## DayText ~ StartTime

## DayText ~ Quota

## DayText ~ Bidders

## DayText ~ LowestBid

## DayText ~ LowestSuccessfulBid

## DayText ~ HighestBid

## DayText ~ BpQ

## LessonTime ~ StartTime

## LessonTime ~ Quota

## LessonTime ~ Bidders

## LessonTime ~ LowestBid

## LessonTime ~ LowestSuccessfulBid

## LessonTime ~ HighestBid

## LessonTime ~ BpQ